HDMI to HDMI only working with second monitor attached
I have an Asrock ION 330 HT BD with a Sony Bravia 720p attached (HDMI to HDMI). When I start up my PC, the screen remains black. Only after I plug in a second monitor, both screens work just fine. When I pull the second monitor out, the Bravia also stops getting a signal. Seems a bit weird.. How can I get it to work with just the Bravia attached?